Green tire conveyance dolly

Abstract

To provide a green tire conveyance dolly that prevents deformation of a green tire and improves stability during conveyance and workability during taking in / out of the green tire.SOLUTION: A dolly for conveying a green tire T in an upright position includes: a frame having a plurality of wheels 12; a fixed bar 4, fixed to a back side of the frame 2 so as to extend in a horizontal direction; a movable bar 6 disposed so as to freely swing around an axis parallel to a center axis of the green tire T while extending in the horizontal direction on a front side of the frame 2; a fabric 8 stretched between the fixed bar 4 and the movable bar 6; and an arc-shaped receiving plate 9 disposed in a lower region of the fabric 8 and curved along an outer peripheral surface of the green tire T. A maximum height of the movable bar 6 is set lower than that of the fixed bar 4.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a green tire carrier used when transporting a green tire from a molding process to a vulcanization process. More specifically, the present invention relates to a green tire carrier that suppresses deformation of the green tire and enables improvement of stability during transportation and workability during loading and unloading.

Background Art

[0002] Conventionally, when transporting a green tire from a molding process to a vulcanization process and storing it as necessary, a carrier is used that holds the green tire in a state where the central axis is vertical (see, for example, Patent Document 1). In such a carrier, if a rigid support member disposed on the frame directly contacts the green tire, the green tire will be deformed, and the uniformity of the tire after vulcanization will deteriorate.

[0003] On the other hand, a carrier has been proposed that includes a fabric stretched between a pair of supports disposed on the frame and on which the green tire is loaded (see, for example, Patent Document 2). According to such a carrier, since the green tire is held so as to be wrapped by the fabric, its deformation can be suppressed. However, when the green tire is held by the fabric, there are drawbacks that the stability of the green tire during transportation is poor and the workability during loading and unloading of the green tire is poor.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] An object of the present invention is to provide a green tire carrier that can suppress deformation of a green tire and improve stability during transportation and workability during loading and unloading.

Means for Solving the Problems

[0006] The green tire carrier of the present invention for achieving the above object is a carrier for transporting a green tire in an upright state, and includes a frame having a plurality of wheels, a fixed bar fixed to the back side of the frame so as to extend in the horizontal direction, and a movable bar disposed swingably around an axis parallel to the central axis of the green tire while extending in the horizontal direction on the front side of the frame, a fabric stretched between the fixed bar and the movable bar, and an arcuate receiving plate disposed in a lower region of the fabric and curved along the outer peripheral surface of the green tire, and the maximum height of the movable bar is set lower than that of the fixed bar.

Effects of the Invention

[0007] In the present invention, since the green tire is held so as to be wrapped by the fabric stretched between the fixed bar and the movable bar, deformation of the green tire can be suppressed and the uniformity of the tire after vulcanization can be improved. Further, in the lower region of the fabric, an arcuate receiving plate curved along the outer peripheral surface of the green tire is provided, so that displacement of the green tire held by the fabric is restricted by the receiving plate, and the stability of the green tire during transportation can be enhanced. This receiving plate has an arcuate shape and indirectly contacts the green tire via the fabric, so it does not cause deformation of the green tire. Furthermore, since the maximum height of the movable bar located on the front side of the frame is set lower than that of the fixed bar located on the back side of the frame, loading and unloading of the green tire are easy, and workability during loading and unloading of the green tire can be improved.

[0008] In the present invention, it is preferable that the radius of curvature of the receiving plate is in the range of 300 mm to 500 mm. By setting the radius of curvature of the receiving plate within the above range, the contact pressure between the receiving plate and the green tire can be reduced, and deformation of the tread portion of the green tire can be effectively prevented.

[0009] In the present invention, it is preferable that the receiving plate is fixed to the frame via a buffer member. By interposing a buffer member between the receiving plate and the frame in this way, the contact pressure between the receiving plate and the green tire can be reduced, and deformation of the tread portion of the green tire can be effectively prevented.

[0010] In the present invention, it is preferable that the receiving plate is disposed between the central axis of the green tire and the movable bar in the horizontal direction. In a structure where the movable bar located on the front side of the frame is disposed at a lower position than the fixed bar, by disposing the receiving plate between the central axis of the green tire and the movable bar, the stability of the green tire during transportation can be effectively enhanced.

[0011] In the present invention, in a state where the green tire is loaded on the fabric, when the angle formed by the straight line passing through the central axis of the green tire and the central axis of the fixed bar with respect to the horizontal direction is θ1, and the angle formed by the straight line passing through the central axis of the green tire and the central axis of the movable bar with respect to the horizontal direction is θ2, it is preferable that the angles θ1 and θ2 are respectively in the ranges of 0° ≤ θ1 ≤ 45° and 0° ≤ θ2 ≤ 60°. Thereby, while firmly holding the green tire, the workability during loading and unloading of the green tire can be improved.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Mode for Carrying Out the Invention

[0013] Hereinafter, the configuration of the present invention will be described in detail with reference to the accompanying drawings. FIGS. 1 to 5 show a green tire carrier truck according to an embodiment of the present invention.

[0014] As shown in FIGS. 1 to 5, the green tire carrier truck of the present embodiment is a truck for carrying a green tire T in a state where the central axis O is horizontal. This green tire carrier truck includes a frame 2 having a plurality of wheels 1. At least a part of the plurality of wheels 1 is preferably configured to be rotatable. The frame 2 has a cubic frame structure. A plurality of partition members 3 are provided on the frame 2, and a plurality of green tire loading areas are partitioned by these partition members 3. The embodiments of FIGS. 1 to 5 are configured to be able to load four green tires T, but the number thereof is not particularly limited.

[0015] In the above green tire carrier, a fixed bar 4 is fixed to the back side (the right side in FIG. 1) of the frame 2 so as to extend horizontally. On the other hand, on the front side of the frame 2 (the left side in FIG. 1), a pair of arms 5 swingably connected to the lower part of the frame 2 are installed, and a movable bar 6 extending horizontally is attached to the tip ends of the pair of arms 5. Therefore, the movable bar 6 is configured to be swingable around an axis parallel to the central axis O of the green tire T. Further, on the front side of the frame 2, stoppers 7 extending horizontally are provided at positions corresponding to the respective movable bars 6, and the swinging of the pair of arms 5 is restricted by these stoppers 7, and the lowering of the movable bar 6 is restricted. A cloth 8 for loading the green tire T is stretched between the fixed bar 4 and the movable bar 6. In the lower region of the cloth 8, an arcuate receiving plate 9 curved along the outer peripheral surface of the green tire T is disposed. This receiving plate 9 is fixed to the frame 2 via a buffer member 10, for example. The movable bar 6 is displaced upward when the green tire T is loaded on the cloth 8 and the cloth 8 sinks, but the maximum height of the movable bar 6 is set lower than that of the fixed bar 4. Further, a handle 11 for operation is provided on the upper part of the frame 2.

[0016] Next, the usage method of the above-described green tire carrier will be described. The green tire T molded in the molding process is placed on the cloth 8 from the front side of the frame 2. As a result, the cloth 8 sinks and the movable bar 6 is displaced upward, and the green tire T is held on the cloth 8. When transporting the green tire T from the molding process to the vulcanization process, or when temporarily storing the green tire T, the green tire carrier is moved to a desired position by operating the handle 11. The green tire T is taken out from the front side of the frame 2.

[0017] In the above-described green tire carrier, since the green tire T is held so as to be wrapped by the fabric 8 stretched between the fixed bar 4 and the movable bar 6, deformation of the green tire T can be suppressed, and the uniformity of the tire after vulcanization can be improved. Further, in the lower region of the fabric 8, an arcuate receiving plate 9 that is curved along the outer peripheral surface of the green tire T is provided. Therefore, displacement of the green tire T held by the fabric 8 is restricted by the receiving plate 9, and the stability of the green tire T during transportation can be enhanced. Since the receiving plate 9 has an arcuate shape and indirectly contacts the green tire T via the fabric 8, it does not cause deformation of the green tire T. Furthermore, since the maximum height of the movable bar 6 located on the front side of the frame 2 is set lower than that of the fixed bar 4 located on the back side of the frame 2, it is easy to take in and out the green tire T, and the workability when taking in and out the green tire T can be improved.

[0018] In the above green tire carrier, it is preferable that the radius of curvature R1 of the receiving plate 9 is in the range of 300 mm to 500 mm. By setting the radius of curvature R1 of the receiving plate 9 within the above range, in various tires including passenger car tires and small truck tires, the contact pressure between the receiving plate 9 and the green tire T can be reduced, and deformation of the tread portion of the green tire T can be effectively prevented. Note that the radius of curvature R1 of the receiving plate 9 is preferably larger than the radius R of the green tire T to be loaded within the above numerical range. Also, the arc length (circumferential length in the tire direction) of the receiving plate 9 is not particularly limited, but it is preferably in the range of 10° to 90°, more preferably in the range of 30° to 60° with respect to the center of the arc of the receiving plate 9. As actual values, for example, it is preferably in the range of 10 mm to 500 mm, more preferably in the range of 150 mm to 500 mm. The width (length in the tire width direction) of the receiving plate 9 is not particularly limited, but it is preferably in the range of 100 mm to 500 mm, more preferably in the range of 250 mm to 300 mm.

[0019] In the above-mentioned green tire carrier, it is preferable that the receiving plate 9 is fixed to the frame 2 via a buffer member 10. By interposing the buffer member 10 between the receiving plate 9 and the frame 2 in this way, the contact pressure between the receiving plate 9 and the green tire T can be reduced, and deformation of the tread portion of the green tire T can be effectively prevented. As the buffer member 10, for example, it is preferable to adopt a spring, but in addition, it is also possible to adopt a rubber member, a sponge member, or the like. In the case of a spring, a single spring can be installed at a position corresponding to the central portion in the tire width direction, or two springs can be installed at positions corresponding to both end portions in the tire width direction. In the latter case, it is possible to enhance the stability of the green tire T.

[0020] In the above-mentioned green tire carrier, it is preferable that the receiving plate 9 is disposed between the central axis O of the green tire T and the movable bar 6 in the horizontal direction. In a structure where the movable bar 6 located on the front side of the frame 2 is disposed at a position lower than the fixed bar 4, by disposing the receiving plate 9 between the central axis O of the green tire T and the movable bar 6, the stability of the green tire T during transportation can be effectively enhanced. Further, the height position of the receiving plate 9 may be set such that the receiving plate 9 comes into contact with the fabric 8 in a state where the green tire T is placed on the fabric 8. Therefore, it is preferable that the height position of the receiving plate 9 from the frame 2 is configured to be adjustable.

[0021] In the above green tire carrier, as shown in FIG. 5, when the green tire T is loaded on the fabric 8, if the radius of the green tire T is R, the angle formed by the straight line passing through the central axis O of the green tire T and the central axis of the fixed bar 4 is θ1 with respect to the horizontal direction, and the angle formed by the straight line passing through the central axis O of the green tire T and the central axis of the movable bar 6 is θ2 with respect to the horizontal direction, it is preferable that the angles θ1 and θ2 are respectively in the ranges of 0° ≤ θ1 ≤ 45° and 0° ≤ θ2 ≤ 60°. In this case, the height L1 from the lower end position of the green tire T to the fixed bar 4 on the back side is L1 = R + R×sinθ1, and the height L2 from the lower end position of the green tire T to the movable bar 4 on the front side is L2 = R - R×sinθ2, and the height positions of both are optimized. Thereby, while firmly holding the green tire T, the workability during loading and unloading of the green tire T can be improved. When the angles θ1 and θ2 are out of the above ranges, it becomes difficult to achieve both the stability during transportation of the green tire T and the workability during loading and unloading.

Example

[0022] An operation of transporting a green tire formed in the manufacturing process of a pneumatic tire of tire size 275 / 55R20 was performed using the green tire carriers of the conventional example, comparative example, and Examples 1 to 3, and further vulcanization of the transported green tire was carried out.

[0023] The conventional example is a carrier truck having a structure in which a green tire is supported from below by a rigid support member disposed on a frame. The comparative example is a carrier truck having a structure in which a green tire is placed on a fabric stretched between a pair of supports disposed on a frame. Examples 1 to 3 are carrier trucks having a fixed bar fixed to the back side of the frame, a movable bar swingably disposed around an axis parallel to the central axis of the green tire on the front side of the frame, a fabric stretched between the fixed bar and the movable bar, and an arcuate receiving plate disposed in the lower region of the fabric, and the maximum height of the movable bar is set lower than that of the fixed bar (see FIGS. 1 to 5). In Examples 1 to 3, the arrangement angle θ1 of the fixed bar, the arrangement angle θ2 of the movable bar, the radius of curvature R1 of the receiving plate, and the presence or absence of a buffer member (spring) were made different as shown in Table 1.

[0024] Regarding the carrier trucks of the above-described conventional example, comparative example, and Examples 1 to 3, the dimensional stability of the green tire, the stability during transportation, the workability during removal, and the quality of the vulcanized tire were evaluated by the following methods, and the results are shown together in Table 1.

[0025] Dimensional stability of the green tire: Regarding the carrier trucks of the conventional example, comparative example, and Examples 1 to 3, after loading the green tire on the carrier truck and leaving it for 3 hours, the outer diameter was measured, and the change amount of the outer diameter before and after loading was determined. Regarding the change amount of the outer diameter, the average value of 24 tires was determined respectively. The evaluation results were indicated by "○" when the change amount was 10 mm or less, "△" when the change amount exceeded 10 mm and was 20 mm or less, and "×" when the change amount exceeded 20 mm.

[0026] Stability during transportation: Regarding the carrier trucks of the conventional example, comparative example, and Examples 1 to 3, when loading 24 green tires on the carrier truck and transporting them, the sway of the green tire was visually confirmed. The evaluation results were indicated by "◎" when the sway was very small, "○" when the sway was small, and "×" when the sway was large.

[0027] Workability during removal: Regarding the carrier trucks of the conventional example, comparative examples, and Examples 1 to 3, when six workers each carried out the operation of taking out 24 green tires from the carrier trucks, a sensory evaluation on the workability was conducted with a full score of 5 points, and the average value was obtained. A larger evaluation score means better workability during the taking-out operation. The evaluation results were indicated as "◎" when the average value of the evaluation scores exceeded 4 points, "○" when the average value of the evaluation scores was less than 4 points and exceeded 3 points, "△" when the average value of the evaluation scores was less than 3 points and exceeded 2 points, and "×" when the average value of the evaluation scores was less than or equal to 2 points.

[0028] Quality of vulcanized tires: The carrier trucks of the conventional example, comparative examples, and Examples 1 to 3 were used for transporting green tires. After vulcanizing 24 tires each, the tire appearance was visually confirmed, and the occurrence rate of vulcanization molding defects was determined. The evaluation results were shown as an index with the conventional example set as 100 using the reciprocal of the occurrence rate of vulcanization molding defects. A larger value of this index means a lower occurrence rate of vulcanization molding defects and better quality of the vulcanized tires.

[0029] [Table 1]

[0030] As can be seen from Table 1, in the carrier trucks of Examples 1 to 3, in comparison with the conventional example, the deformation of the green tires was suppressed. As a result, the quality of the vulcanized tires was good, and the stability during transportation and the workability during taking-out were good. On the other hand, in the carrier trucks of the comparative examples, although the deformation of the green tires was suppressed, the stability during transportation and the workability during taking-out were poor.

[0031] This disclosure includes the following inventions [1] to [5]. The invention [1] is a trolley for transporting green tires in an upright state, comprising a frame with a plurality of wheels, a fixed bar fixed to the back side of the frame so as to extend horizontally, a movable bar disposed swingably around an axis parallel to the central axis of the green tire while extending horizontally on the front side of the frame, a fabric stretched between the fixed bar and the movable bar, and an arc-shaped receiving plate disposed in the lower region of the fabric and curved along the outer peripheral surface of the green tire, wherein the maximum height of the movable bar is set lower than that of the fixed bar. The invention [2] is the green tire transport trolley according to the invention [1], characterized in that the radius of curvature of the receiving plate is in the range of 300 mm to 500 mm. The invention [3] is the green tire transport trolley according to the invention [1] or [2], characterized in that the receiving plate is fixed to the frame via a buffer member. The invention [4] is the green tire transport trolley according to any one of the inventions [1] to [3], characterized in that the receiving plate is disposed horizontally between the central axis of the green tire and the movable bar. The invention [5] is the green tire transport trolley according to any one of the inventions [1] to [4], characterized in that when the angle formed by the straight line passing through the central axis of the green tire and the central axis of the fixed bar with respect to the horizontal direction is θ1, and the angle formed by the straight line passing through the central axis of the green tire and the central axis of the movable bar with respect to the horizontal direction is θ2, the angles θ1 and θ2 are respectively in the ranges of 0° ≤ θ1 ≤ 45° and 0° ≤ θ2 ≤ 60°.

Explanation of reference numerals

[0032] 1 Wheel 2 Frame 3 Partition member 4 Fixed bar 5 Arm 6 Movable bar 7 Stopper 8 Fabric 9 Receiving plate 10 Buffer member 11 Handle T Green Tire

Claims

1. A trolley for transporting a green tire in an upright state, comprising a frame having a plurality of wheels, a fixed bar fixed to the rear side of the frame so as to extend horizontally, and a front side of the frame. A movable bar that is swingably disposed around an axis parallel to the central axis of the green tire while extending horizontally, a fabric stretched between the fixed bar and the movable bar, and disposed in a lower region of the fabric and along the outer peripheral surface of the green tire. A green tire transport trolley, characterized in that it has an arcuate receiving plate that is curved and the maximum height of the movable bar is set lower than that of the fixed bar.

2. The green tire transport trolley according to claim 1, characterized in that the radius of curvature of the receiving plate is in the range of 300 mm to 500 mm.

3. The green tire transport trolley according to claim 1 or 2, characterized in that the receiving plate is fixed to the frame via a buffer member.

4. The green tire transport trolley according to claim 1 or 2, characterized in that the receiving plate is disposed horizontally between the central axis of the green tire and the movable bar.

5. When the angle formed by the straight line passing through the central axis of the green tire and the central axis of the fixed bar with respect to the horizontal direction is θ1, and the angle formed by the straight line passing through the central axis of the green tire and the central axis of the movable bar with respect to the horizontal direction is θ2, the green tire transport trolley according to claim 1 or 2, characterized in that the angles θ1 and θ2 are respectively in the ranges of 0° ≤ θ1 ≤ 45° and 0° ≤ θ2 ≤ 60°.

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